1. This invention relates to an electric mirror angle adjusting device for a mirror mounted on a fender or the like, of a motor vehicle.
2. Description of the Prior Art
Conventional electric mirror angle adjusting devices have comprised a pair of adjusting members for the adjustment of the mirror angle each of which is connected with an electric motor. Because these devices need two electric motors, they have been too expensive and bulky.
Recently, the whole device has been made smaller and lighter by using a single electric motor, the driving force of which is selectively transmitted to either of the adjusting members as found in U.S. Pat. No. 3,972,597, U.S. Pat. No. 4,056,253 and Japanese Patent Laid-Open Publication No. Sho 53-83239. In the former two, a worm wheel is attached to each adjusting member, and a worm gear, attached to the output shaft of an electric motor, is selectively engaged with either of the worm wheels. In the latter, each adjusting member is provided with a worm wheel and a worm gear in meshing contact therewith, and a change-over gear connected with the output shaft of an electric motor is alternately engaged with the worm gears. In these devices of the prior art in which the worm gear or change-over gear is shifted, its teeth are liable to collide with those of fixed gears. Therefore, the change-over is not performed smoothly, and the gears are liable to be damaged. In such mechanisms, it is desirable to keep all the gears in meshing contact with each other and to hold them firmly in a housing in order to transmit the driving force smoothly and accurately. A device disclosed by U.S. Patent No. 3,857,631 uses belts in place of the adjusting members to adjust the mirror angle. However, it is rather complicated in construction with several gears, pulleys, etc. and is not necessarily easy to manufacture.